1. Field of the Invention
This invention relates generally to computer-implemented data processing file management systems and, more specifically, to an Automatic Class Selection (ACS) system employing a declarative ACS filter.
2. Discussion of the Related Art
Many useful data file storage management techniques are known in the art. In particular, file classification schemes for associating selected data files to particular storage groups and management classes are necessary for the efficient management of large database systems such as the Multiple Virtual Storage (MVS) Systems Managed Storage (SMS) system introduced by International Business Machines Corporation.
In the MVS/SMS, data file management includes routines for Automatic Class Selection (ACS) based on data file attributes. These ACS routines are used to determine the SMS classes and storage groups for data sets in a SMS complex. This procedure automates and centralizes the determination of SMS classes and storage groups and also facilitates the conversion of data files to a SMS environment.
Unfortunately, these ACS routines are procedural programming language specifications that must be executed to link or assign a management or storage class to a data file. The assigned classes are then stored in a database for later reference by the SMS system. This has several disadvantages. First, there is no provision for automatically updating the class assignments in response to changes in data file characteristics over time. Secondly, the procedure requires both the classification selection step and a database reference step which is inefficient. Finally, the ACS routine cannot be modified without resorting to programming expertise that may not be available to all users. The MVS/SMS ACS routines may be appreciated with reference to U.S. Pat. No. 5,018,060 issued to Gelb et al., and to MVS/ESA Storage Administration Reference, Version 3, Release 1, Chapter 8: "Defining ACS Routines", pp. 59-62, International Business Machines Corp. (SC 26-4514), Armonk, N.Y.
Other practitioners have proposed file management systems that provide similar data file attribute linking systems. For instance, the Personally Safe'n'Sound (PSNS) tool in the Operating System/2 (OS/2) Tools Repository provides a rule-based backup system that associates backup attributes with data files using wild-card specifications for directory paths and file names only. Although this provides some automation of the data file backup process, it offers no provision to accommodate attributes other than name and path or changes in data file characteristics. The PSNS file association technique may be appreciated with reference to Lucy Bannell et al., Personally Safe'n'Sound Users Guide, Release 0.1.2, Apr. 26, 1991, Chapter 8: "Rule Book Configuration", pp. 19-26, International Business Machines Corp., Armonk, N.Y.
Similarly, the OS/2 File Manager and related file management products provide means for associating executable programs with file names using wild-card notation to determine which programs are to be executed against a selected data file but no provision is made for discriminating among data file attributes other than file name. The OS/2 file association technique may be appreciated with reference to Operating Systems/2 Extended Edition Version 1.3 Users Guide, Vol. 1: Base Operating System, Chapter 5: "Managing Files and Directories", pp. 5.38-5.40, International Business Machines Corp., Armonk, N.Y.
In U.S. Pat. No. 5,047,918, Mayer D. Schwartz et al., disclose a file management system that provides for data file linkages according to user-definable relationships. Schwartz et al., require an external database in which to store these definable relationships and include in this database an archive of data file versions and their links referred back according to time of creation. Thus, Schwartz et al., neither teach nor consider an efficient file attribute management system that is dynamically responsive to changes in data file attributes.
In Reference U.S. Pat. No. 5,063,523, Milan J. Vrenjak teaches a data communication network management system that permits a user to establish pattern matching rules for filtering incoming events. Again, even if Vrenjak's method were applicable to data file management without undue experimentation, he does not consider dynamic reallocation of linkages.
In U.S. Pat. No. 4,701,840, William E. Boebert et al., disclose a secure data processing system architecture including a secure processing unit for storing and comparing system file attributes and user entity attributes. In U.S. Pat. No. 4,468,732, Norman Raver discloses an automated logical file design system for minimizing database redundancy by sorting data attributes. In the above-cited U.S. Pat. No. 5,018,060, Jack P. Gelb et al., discloses a method for allocating data storage space using implied allocation attributes associated with user-selected parameters. In U.S. Pat. No. 5,115,505, Thomas P. Bishop et al., discloses a multiprocessor dynamic load balancing system employing processor assignment based on allocation parameters inserted into a program object file stored in the file system. In U.S. Pat. No. 5,093,779, Naoki Sakurai discloses a computer file system that allocates files between a high-ranking directory and a low-ranking directory based on file attributes. None of these practitioners teaches or considers a method for automatic data file class selection based on user-selected data file attributes other than file name and path.
Accordingly, there exists a clearly-felt need in the art for a simple user-specified association between data files and file management classes that does not rely on external storage of class linkages or custom-programmed selection routines and that is responsive to dynamic changes in data file attributes. The related problems and deficiencies are clearly felt in the art and are solved by this invention in the manner described below.